The present invention relates to tamper-indicating closures, to methods of manufacturing such closures, and to a package that includes such a closure on a container.
It is conventional to form a tamper-indicating closure having a band connected to the skirt of the closure by integral frangible bridges or webs. The band has a stop element (e.g., a flange or a bead) that engages a bead on the container to resist unthreading of the closure, so that removal of the closure ruptures the frangible elements that connect the band to the closure skirt. U.S. Patent Re 33,265, assigned to the assignee hereof, discloses a tamper-indicating closure of this character, in which the tamper-indicating band is completely severed from the closure skirt and remains with the container upon removal of the closure from the container. U.S. Pat. No. 5,295,600, also assigned to the assignee hereof, discloses a tamper-indicating closure in which the tamper-indicating band remains connected to the closure skirt and is removed from the container with the closure.
Although tamper-indicating closures of the types disclosed in the noted patents have enjoyed substantial commercial acceptance and success in the art, further improvements remain desirable. In particular, problems are encountered when employing this type of closure with a container in so-called wet finish applications, in which liquid may spill during or after the filling operation onto the outside surface of the container finish so as to be disposed between the container finish and the closure skirt after capping. Wet finish situations of this type are encountered during hot-fill, cold-fill and aseptic-fill situations, in which the containers are filled close to the brim or to overflow prior to capping. Wet finish situations can also be encountered during filling operations in which liquid may drip from the filling machinery onto the container finish. In wet-finish situations of this type, problems are encountered in connection with draining and drying of the area between the outer surface of the container finish and the closure skirtxe2x80x94i.e., between the threads on the container finish and skirt, and around the tamper-indicating band and the stop element. Liquid trapped within this area can result in growth of mold and mildew. This drainage problem is particularly exacerbated in situations in which the self-resiliency of the closure biases the stop flange into opposed engagement with the so-called A1 diameter of the container finish. While wet finish applications are not usually recommended by closure manufacturers because of the potential for entrapment of product in the closure threads and the consumer problems that result therefrom, the present invention will help alleviate the potential for product entrapment when the product filler finds it necessary to use such a filling process.
It is a general object of the present invention to provide a closure and method of manufacture that facilitate drainage of liquid products after filling and capping of the closure and container package. Another and related object of the present invention is to provide a closure and method of manufacture that achieve the foregoing objectives while retaining the advantages of the closures disclosed in the above-noted patents in terms of ease of application to the container finish after filling (lower top load and lower temperature) and whole or partial rupture of the tamper-indicating band from the closure skirt to provide the tamper-indicating feature. Yet another object of the present invention is to provide a package, which includes a closure and a container, that is particularly well adapted for use in conjunction with wet finish applications as described.
A tamper-indicating closure of integrally molded plastic construction in accordance with presently preferred embodiments of the invention includes a base wall having a peripheral skirt with internal threads for engaging external threads on a container finish. A tamper-indicating band is connected to the edge of the skirt by frangible means such as a plurality of circumferentially spaced integral frangible bridges. A stop flange extends axially outwardly and radially inwardly from an edge of the band remote from the skirt for inversion and engagement with a bead on the container finish. The stop flange is in the form of a circumferentially continuous base of uniform thickness circumferentially of the band, and either uniform or increasing thickness radially and axially of the band. A plurality of circumferentially spaced lugs are integral with and extend from the base. The lugs widen uniformly from zero thickness at the band to a maximum thickness at the free edge of the flange. The lugs are thus disposed for opposed abutting engagement with the A1 diameter of the container finish beneath the A bead on the container finish. The channels or serrations between the lugs permit drainage of liquid from the area between the skirt and the container finish.
In the preferred embodiments of the invention, the lugs are of uniform dimension circumferentially of the flange, and spacing between the lugs is of uniform dimension circumferentially of the flange. The uniform circumferential dimension of the lugs is preferably less than the uniform circumferential spacing between the lugs to enhance the area for drainage of liquid between the flange and the opposing surface of the container finish. The lugs thus serve to space the flange base from the container finish, and to strengthen the flange base upon abutting engagement with the finish A bead during removal of the closure from the container finish. The thickness of the lugs at the free edge of the flange may be either greater than or less than the thickness of the base at the free edge of the flange. Thickness of the flange base may be either uniform axially and radially of the flange, or may increase axially and radially of the flange from the band to the free edge of the flange. The free edge of the flange preferably is circumferentially continuous without scallops or indentation, and lies entirely in a plane parallel to the base wall.
In accordance with another aspect of the present invention, a package is provided that comprises a container having a finish with external threads and an external bead disposed beneath the threads, and a tamper-indicating closure that includes a base wall having a peripheral skirt with internal threads securing the closure to the container. A tamper-indicating band is connected by frangible means to an edge of the skirt, and a stop flange extends axially and radially from an edge of the band remote from the skirt. The stop flange includes a circumferentially continuous base of uniform thickness circumferentially of the band, and either uniform or increasing thickness radially and axially of the band. A plurality of circumferentially spaced lugs integrally extend from the base into opposed abutting engagement with the opposed surface of the container finish beneath the bead. The lugs widen uniformly from zero thickness at the band to a maximum thickness at the free edge of the flange. The present invention also contemplates a method of manufacturing a tamper-indicating closure of the type described in the preceding paragraph.
In accordance with yet another aspect of the present invention, a method of filling and capping a container includes the step of providing a container having a finish with external threads and an external bead, and filling the container with liquid to a brim of the finish. A closure is then applied to the container finish, with the closure having a base wall, a skirt with internal threads, a band connected to the skirt by frangible means, and a flange extending from the band for engagement with the container bead. To facilitate drainage of liquid from between the closure skirt and the container finish, the flange on the closure is provided in the form of a circumferentially continuous base of uniform thickness circumferentially of the band, and either uniform or increasing thickness radially and axially of the flange. A plurality of circumferentially spaced lugs are formed integrally with and extend from the base for abutting engagement with an opposing surface of the container finish beneath the bead. The lugs widen uniformly radially and axially of the flange from zero thickness at the band to a maximum thickness at the free edge of the flange.
The invention, together with additional objects, features and advantages thereof, will be best understood from the following description, the appended claims and the accompanying drawings in which:
FIG. 1 is a fragmentary perspective view of a container and closure package in accordance with a presently preferred embodiment of the invention;
FIG. 2 is a fragmentary sectional view that illustrates the container finish and closure in the package of FIG. 1;
FIG. 3 is a partially sectioned side elevational view of the closure in the package of FIGS. 1 and 2 as moldedxe2x80x94i.e., before stop flange inversion;
FIG. 4 is a fragmentary sectional view of the portion of the closure within the circle 4 in FIG. 3;
FIG. 5 is a fragmentary plan view taken from the direction 5xe2x80x945 in FIG. 4;
FIG. 6 is a fragmentary sectional view that bisects a closure and container finish in accordance with another embodiment of the invention;
FIG. 7 is a partially sectioned side elevational view of the closure in the package of FIG. 6 as molded;
FIG. 8 is a fragmentary sectional view of the portion of FIG. 7 within the circle 8;
FIG. 9 is a fragmentary plan view taken from the direction 9xe2x80x949 in FIG. 8; and
FIG. 10 is a fragmentary sectional view taken substantially along the line 10xe2x80x9410 in FIG. 7.